swanson



March 30, 1948. E. E. SWANSON Filed Sept. 11, 1945 far] Jzaamon Patented Mar. 30, 1948 LAP Earl E. Swanson, North Hollywood, Calif., as-

signor to Ruth C. Swanson, North Hollywood,

Calif.

Application September 11, 1945, Serial No. 615,647

3 Claims. 1

My invention relates to laps, such as are used in drill presses and other operating machines for correcting and smoothing out and even slightly enlarging bores for the purpose of securing precision and perfect fit of a part operating therein.

Among the salient objects of my invention are: to provide a simple, practical and economical lap for the purposes indicated which has a yieldableness and resiliency of the body portion on which the lapping compound is placed, whereby to better insure its effectiveness as it is operated in the bore or cavity being treated; to provide a lap which will remain straight and will not follow an elongated hole, and which will remove all high spots in such hole; to provide a lap which will not stick or catch in the work so as to throw the work piece and possibly injure the operators hand, but will yield sufficiently to avoid such accident; to provide a lap which will last longer because of its flexibility and adaptability to the work to be done thereby; and, in general, to provide a lap which is practical, eflicient and inexpensive.

In order to further explain my invention, I have illustrated the same on the accompanying sheet of drawings in which Figure 1 is a, side elevation of a lap embodying my invention, with the body portion in vertical section;

Figure 2 is an end elevation; and

Figures 3 and 4 are cross sectional views taken, respectively, on the lines 3-3, and 4-4, of Fig. 1.

Referring now in detail to the drawings, my lap as here shown for explanatory purposes, include-s a, main body or shank 5, which may be of any desired size or shape, as may be required for the machine in which it is to be used, having the working body 6 of cylindrical form and hollow, and being split longitudinally, as at 1, and circumferentially cut, as at 8, for a part of its circumference, as will be understood from Figs. 1 and 3. This leaves two portions, or Wings, 6', 6' free to yield in a, compressible or expansible manner.

In order to increase the resiliency of this portion of said work body, I provide a split spring insert body 9, having at its split edges lip portions 9, 9' which extend into the split 1 of said work body, as clearly shown in Fig. 4. This not only gives resiliency and firm yieldableness to said work body, but these lip portions prevent any turning of said insert.

The lapping compound, whatever it may be, is put upon the surface of the work body and then it is operated in the usual manner in the work, as will be understood by all users of laps, or like mechanisms.

I do not limit my invention to the exact details of construction shown for explanatory purposes, except as I may be limited by the hereto appended claims.

I claim:

1. A lap of the character shown and described including a body the upper part of which constitutes the supporting shank and the lower part of which is hollow and constitutes the working body, the working body part being split longitudinally and also being cut circumferentially from said split in opposite directions therefrom for a, part of the circumference of said hollow body and leaving the uncut portion as the supporting connection between the working body and the shank part of said body, and providing two wing portions to function as the work-portion of said work body.

2. A lap of the character shown and described including a body the upper part of which constitutes the supporting shank and the lower part of which is hollow and constitutes the working body, the working body part being split longitudinally at one side and also being cut circumferentially in opposite directions from said split to provide two working wings, the uncut portion of the body connecting it integrally with the shank part of said body, and a spring insert of split cylindrical form to lit in said working body to give increased resiliency.

3. A lap of the character referred to consisting of a body the upper portion of which constitutes the shank for supporting said lap and the lower portion of which is hollow and constitutes the working body, the hollow working body being split longitudinally at one side and also: cut circumferentially at the upper end of the hollow part of said working body for a portion of its circumference, whereby to provide two yielding wings to constitute the working body, the uncut portion of the wall of said hollow body portion constituting the supporting connection of the working body with the shank, and a spring metal cylindrical insert, also split, to be inserted into said hollow working body to give increased resiliency to said working body, the split edge of said insert being inserted in the split of said working body to prevent its turning relative to said working body.

EARL E. SWANSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,318,531 Bockius Oct. 14, 1919 

